Dazomet compositions

ABSTRACT

A solid body of dazomet for use in internal remedial treatments of wood and methods of applying such solid bodies to wooden structures and manufacturing such solid bodies. The solid bodies can be easily transported and inserted into treatment holes in utility poles, wooden pilings, and other wooden structures, delivering a precise, accurate dose of insecticide and fungicide that combats internal decay in the wood.

TECHNICAL FIELD

The present invention pertains to the protection of wooden structuresfrom internal decay caused by insects, fungi, and other pests. Moreparticularly, the present invention is directed towards a compositionand a product for the internal remedial treatment of wood comprising asolid body of the disclosed dazomet compositions and the insertion of asolid body of dazomet into a treatment hole in a wooden structure.

BACKGROUND OF THE INVENTION

Dazomet (Tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione) is anon-selective fumigant with several uses. Fumigants form gasses afterapplication that have biocidal activity. When dazomet is applied, it isquickly broken down into several active degradation products. The majordegradation product formed by dazomet is methyl isothiocyanate (MITC).MITC is highly volatile and is responsible for the fumigant propertiesof dazomet. In the soil, dazomet exhibits fungicidal, herbicidal andnematicidal properties. Unlike other soil fumigants, dazomet is appliedas a dry granule and incorporated into the soil or applied to the soilsurface and watered into the soil to activate it. Dazomet is alsoregistered as an algaecidal, bacteriocidal, fungicidal, microbicidal,and mildewcidal agent for use during the production of pulp and paper,treatment for coatings, adhesives, epoxy flooring compounds, slurries,and high viscous suspensions, biocidal treatments in petroleumoperations and recirculating water cooling systems and as a remedialtreatment of wooden utility structures.

Long-term test results have demonstrated the excellent efficacy ofdazomet as a wood pole fumigant. The addition of an accelerant, such ascopper naphthenate, increases the release of fumigant early in thetreating cycle, thus eliminating concerns from earlier testing that theproduct was not breaking down fast enough to deliver a lethal dose tothe inhabiting fungi.

Diffusible preservatives, often containing boron or fluoride compounds,come in a wide spectrum of different forms, including powders, pastes,gels, thickened solutions, and solid rods. Some diffusible preservativetreatments take the form of boron or boron-copper mixtures which aremelted and molded into rods. Other diffusible preservative treatmentsare boron-containing pastes which can be applied to the wooden structureto be preserved and then formed into a desired shape and left tosolidify before application.

Several products using dazomet for remedial treatment of wooden utilitypoles are commercially available. Granular fumigants, such as Osmose'sDuraFume®, contain a crystallized solid dazomet fumigant that decomposesto produce MITC. Application of granular fumigants in the field,however, is cumbersome and inefficient. Like liquid fumigants, granularfumigants must be poured into treatment holes pre-drilled from above,and are also subject to spilling and difficulties in accuratelymeasuring the proper dosage of dazomet to be applied. Granular fumigantsare also subject to clumping and unwanted dust production. Addition ofaccelerants, such as copper naphthenate or copper sulfate to granulardazomet in a utility pole leads to inefficient and sub-optimaldistribution of the accelerant throughout the dazomet granules.

Although boron- and fluoride-based rods overcome the disadvantages ofgranular compositions and have been commercially developed, theformulation of dazomet into compressed solid forms has not succeeded inproducing a product with sufficient hardness, friability and performancenecessary for field use. Oregon State University's Utility Pole ResearchCooperative (UPRC) tested a fumigant “rod” containing dazomet that wassimilar to boron-containing diffusible preservative rods. The UPRC“rods” were prepared by wetting powdered dazomet with water followed bycompression into pellets. Water, however, triggers dazomet decompositionto produce the active MITC biocide, during manufacturing. MITCgeneration prior to application raises is inefficient and potentiallyhazardous. The UPRC pellets exhibited poor friability and hardness whichis unsuitable for commercial applications and normal handling andapplications in the field.

There has long been a need in the utilities industry for an alternativeto granular dazomet formulations that could possibly eliminate some ofthe undesirable handling characterizes of a granular formulation.Although a dazomet rod product could fill the market void as asubstitute for granular systems, no serious efforts to commercializethem have taken place.

The difficulties in formulating a dazomet rod suitable for commercialapplications has resulted in the development of several alternatives toa compressed dazomet rod. In one case, dazomet is packaged intopreformed tubes. For example, Super-Fume Tubes have been developed,based on the same effective and safe granular formula that is appliedfrom jugs (HDPE/HDPP Containers). The tubes use a perforated orgas-permeable outermost packaging material to contain a pre-set dose ofthe granular dazomet product. Another alternative to granular dazomet isOsmose's MITC-FUME®. This product consists of an aluminum tube filledwith solid 97% MITC (instead of dazomet) and capped with an air-tightseal.

Compositions of dazomet suitable for formation of solid dazomet bodies,such as rods, that have properties (such as hardness and friability)suitable for use as commercial wood preservative for the internalremedial treatment of wood are disclosed herein. Methods of producingsuch dazomet compositions and solid bodies and methods for their use inthe remedial treatment of wood utility structures, such as wood utilitypoles, are also disclosed.

SUMMARY OF THE INVENTION

In certain aspects of the invention, a composition comprising a flowablemixture of dazomet(tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione), a lubricant anda binder. In another aspect of the invention, the dazomet is in the formof granules or powders. In another aspect of the invention, thelubricant is an oil or a hydrogenated oil. In one aspect of theinvention, the binder is a carbohydrate, including, monosacharides,oligosaccharides and polysaccharide, including starches, dextrins,maltodextrins, soy flour, dextrose, a polyol or a combination thereof.In another aspect of the invention, the binder is a polysaccharide.

In certain aspects of the invention, the compositions comprise between80 and 96% solid tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione,between 0.5 and 5.0% of a lubricant and between 1 and 15% of a binder.In certain aspects of the invention, the compositions comprise between90 and 96% solid tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione,between 0.5 and 5.0% of an oil and between 1 and 5% of a polysaccharide.In certain aspects of the invention, the compositions comprise between90 and 96% solid tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione,between 0.5 and 5.0% of a saturated oil and between 1 and 5% of apolysaccharide. For example, the hydrogenated oil may be a hydrogenatedvegetable oil. The polysaccharide may be a starch, such asmaltodextrins.

The compositions disclosed herein are compressed into a solid body toproduce a product for the internal remedial treatment of wood. The solidbody may take a form selected from the group consisting of a rod,tablet, pellet and a stick. The disclosed products may have a diameterof about 5 millimeters to about 30 millimeters, a length of about 100millimeters to about 600 millimeters. In one aspect of the invention,the length of the rod is from about 100 millimeters to about 350millimeters. In one aspect of the invention, the length of the rod is2.5-times greater than the diameter of the rod. In one aspect of theinvention, the product has a weight of between 10 and 500 grams. Inanother aspect of the invention, the product may comprise an accelerant,such as a compound, including but not limited to copper naphthenate,copper sulfate, copper carbonate, basic copper carbonate, copperhydroxide, cupric oxide, ammoniacal copper, copper-amine complexes,cuprous oxide, copper oxychloride, copper dimethyldithiocarbamate,copper borate or a zinc compound, including but not limited to zincnaphthenate. The accelerant may be in the form of a solid, dissolvedliquid or copper particles dispersed in an aqueous or non-aqueouscarrier. The product of the invention may be sheathless.

The present invention also provides methods for internal remedialtreatment of wood, comprising the steps of inserting the disclosedproducts into a treatment hole in a wooden structure. In certain aspectsof the invention, the wooden structure contains multiple treatmentholes, and multiple solid bodies of dazomet are inserted into themultiple treatment holes which may be pre-drilled (before application ofthe product). In certain aspects of the invention, the disclosed methodsof the remedial treatment of wood further comprise the step of boringthe multiple treatment holes into the wooden structure. The treatmentholes may have diameters of about 5 millimeters to about 30 millimetersand a depth of about 100 millimeters to about 600 millimeters. Incertain aspects of the invention, the methods comprise the further stepof plugging the treatment hole(s).

In certain aspects of the invention, the disclosed methods furthercomprise the step of adding an accelerant to the treatment hole intowhich the solid body has been inserted. According to one aspect of theinvention, the accelerant is selected from the group consisting of acopper compound and a zinc compound. According to one aspect of theinvention, the product may comprise an accelerant, such as a compound,including but not limited to copper naphthenate, copper sulfate, coppercarbonate, basic copper carbonate, copper hydroxide, cupric oxide,ammoniacal copper, copper-amine complexes, cuprous oxide, copperoxychloride, copper dimethyldithiocarbamate, copper borate or a zinccompound, including but not limited to zinc naphthenate. The accelerantmay be in the form of a solid, dissolved liquid or copper particlesdispersed in an aqueous or non-aqueous carrier. The wooden structuressuitable for treatment by the disclosed methods include but are notlimited to utility poles, pilings, timbers, and railroad ties.

The present invention also provides a method for manufacturing a productessentially free of water for internal remedial treatment of wood,comprising the steps of uniformly blending a mixture of dazomet, alubricant, and a binder; and compressing the blended mixture into asolid body without the addition of water or aqueous solutions. Incertain aspects of the invention, the dazomet is powdered or granulatedand the lubricant is selected from the group consisting of magnesiumstearate, aluminum stearate, calcium stearate, talc, sodium benzoate,glyceryl mono fatty acid, glyceryl monostearate, glyceryl dibehenate,glyceryl palmito-stearic ester, hydrogenated cotton seed oil, castorseed oil, and vinylpyrrolidone-vinyl acetate copolymer. In certainaspects of the invention, the binder is selected from the groupconsisting of maltodextrin, dextrin, pectin, starch, modified starch,and starch derivatives and the mixture contains from about 80 parts toabout 99 parts dazomet, from about 0.5 parts to about 5 parts lubricant,and from about 0.5 parts to about 15 parts binder.

DETAILED DESCRIPTION OF THE INVENTION

Dazomet (3,5-dimethyl-1,3,5,-thiadiazinane-2-thione) is a cyclicdithiocarbamate biocide used in the control of fungi that functions bydecomposing within wood to release MITC, the primary fungitoxiccomponent. When exposed to wood or moist soils, solid dazomet decomposesinto MITC, formaldehyde, carbon disulphide (CS₂), hydrogen sulphide(H₂S), and monethylamine, which interact together. MITC is the majorproduct (approximately 98%) of dazomet decomposition, with a theoreticalmaximum decomposition rate for dazomet of approximately 45% (meaningthat a 210 gram application of dazomet would yield the equivalent of94.5 grams of MITC). The generation and dissipation of MITC from dazometdepends on chemical and physical factors, with the most critical factorsbeing temperature, moisture and pH. In particular, MITC generation anddissipation increases at higher levels of temperature and moisture.Dazomet rapidly hydrolyses in water, with the rate of hydrolysisincreasing at higher levels of pH. In wood, dazomet decomposes torelease MITC at the stoichiometric conversion rate of approximately 45%.

A product for internal remedial treatment of wood, as well as towardsthe methods of using and manufacturing such a product, are disclosedherein. A product for internal remedial treatment of wood, comprising asolid body of dazomet is disclosed. Methods for internal remedialtreatment of wood, comprising the step of inserting a solid body ofdazomet into a treatment hole in a wooden structure are also disclosed.A method for manufacturing a product for internal remedial treatment ofwood, comprising the steps of blending a mixture of dazomet, alubricant, and a binder, and compressing the blended mixture into asolid body are disclosed.

In certain aspects disclosed herein, a product for the internal remedialtreatment of wood comprises a solid body of dazomet that has been formedby compressing powdered dazomet or granular dazomet into a solid body.

As used herein, “solid body” refers to the form of the compressedcompositions disclosed herein, including but not limited to rods,tablets, pellets and or sticks. In certain aspects, the solid body, asused herein, is a shaped body produced by compressing the compositionsdisclosed herein into a desired three-dimensional shape. In variousaspects, the shaped body is selected from the group consisting of a rod,a tablet, a pellet, and a stick. In certain aspects, the shaped body isa rod. However, it would be readily apparent to those skilled in the artthat the solid body of dazomet could be shaped into other forms as well.In one aspect, the rod has a diameter of between about 5 millimeters toabout 30 millimeters, a length of between about 100 millimeters to about6000 millimeters, and a weight of about 10 grams to about 5000 grams. Itwould be readily apparent to one skilled in the art, however, that thedisclosure is not limited to these particular dimensions or shapes. Inone aspect, the dimensions of the solid body of dazomet could becustomized to a particular shape and set of dimensions specified by acustomer.

As used herein, “sheathless” means no covering on the outermost surfaceof a solid body of the compositions disclosed herein, including but notlimited to tubes, wrappers or coatings, including but not limited tometal, plastic or paper tubes, perforated tubes or perforated or gaspermeable (MITC, for example) wrappers or coatings. The compositionsdisclosed herein may specifically exclude tubes, such as plastic, metal,or paper tubes, gas-permeable tubes, perforated tubes, gas permeable(MITC) wrappers, wrappings and coatings.

In certain aspects of the invention, the product for the internalremedial treatment of wood comprises a solvent. In preferred embodimentsof the invention, the solvent is an aqueous solution. However, it wouldbe readily apparent in the art that acetone or other organic solventscould be used. The water solubility of dazomet ranges betweenapproximately 3.5 and 3.9 grams per liter at 20.2° C. and a pH ofbetween 5 and 9. At 25° C., hydrolyzing dazomet has a half-life ofapproximately 6-10 hours at a pH of 5, 2-3.9 hours at a pH of 8, and0.8-1 hours at a pH of 9. In moist, aerobic soil, the half-life ofdazomet is less than 24 hours.

In certain aspects of the invention, the product for the internalremedial treatment of wood comprises an accelerant. Accelerants speedthe decomposition of dazomet into MITC, increasing the rate of diffusionof the MITC in the wood. In aspects of the invention, the accelerant isselected from the group consisting of zinc naphthenate, liquid coppernaphthenate, copper carbonate, copper hydroxide and copper sulfatepowder. In a preferred embodiment of the invention, between about 10 andabout 30 grams of liquid copper naphthenate solution are added to atreatment hole into which a solid body of dazomet has been inserted.

In aspects of the invention, a liquid copper naphthenate solution usedas an accelerant may be made up of between about 0.1% and about 8%liquid copper by weight, and made be water-borne or oil-borne. In apreferred embodiment, the liquid copper naphthenate solution has aliquid copper concentration of about 1% to about 2%. Accelerantscontaining copper enhance the production of MITC by decomposing dazometand reduce the evolution of carbon disulfide (which volatizes rapidly,leaving the wood unprotected). Additionally, some accelerants, such ascopper sulfate, result in MITC production from dazomet even in theabsence of moisture, so such accelerants should be kept separate fromthe dazomet until treatment begins or immediately prior to treatment.

The MITC produced by dazomet is effective in controlling wood fungi andcan rapidly eradicate colonies of decay fungi in wooden structures,including brown-rot fungi, white-rot fungi, and soft-rot fungi. Theapproximate threshold range for MITC to be effective in combatingwood-decay fungi is between about 20 and about 40 μg/g (ppm) ofoven-dried wood sample. Long exposures of dazomet are effective incontrolling fungal growth.

In aspects of the invention, the solid body is an insecticide and anematicide. The MITC produced by dazomet is toxic to and effective inkilling nematodes and insect pests such as army-worms, cut-worms,termites, beetles including powderpost beetles, and ants includingcarpenter ants. Due to dazomet's mode of application to wood, whichprevents exposure to bees, the product is relatively non-toxic andharmless to bees such as honeybees. Additionally, while dazomet hasinitially strong effects on populations of soil-dwelling organisms suchas earthworms and arthropods, these effects are reversible. The endproducts of dazomet's degradation after complete mineralization arebicarbonate, nitrate, and sulphate, which can be considered nutrientsfor plants.

A product for the internal remedial treatment of wood is applied to awooden structure. In certain aspects disclosed herein, as disclosedherein, by inserting or dropping a solid body of the compositionsdisclosed herein into a treatment hole in a wooden structure. In certainembodiments, the wooden structure is a utility pole, piling, timber orrailroad tie, but it would be readily apparent to one skilled in the artthat the products disclosed herein may be applied to any type of woodenstructure for the purposes of combating decay. It would be readilyapparent to one skilled in the art that the products disclosed hereincould be applied to all types and species of wood to combat internaldecay.

In aspects disclosed herein, the treatment holes have been pre-drilledinto the wooden structure. In other aspects of the present invention,methods of applying the solid body to a wooden structure comprise boringor drilling one or more treatment holes into the wooden structure. Whenboring treatment holes into a wooden structure, the utility pole,piling, or other type of wooden structure should be inspected thoroughlyto determine an optimal drilling pattern that avoids metal fasteners,seasoning checks, and severely rotted wood.

In aspects of the invention, boring or drilling the one or moretreatment holes into a utility pole or piling comprises drilling holesof between about 19 and about 22 mm (approximately ¾ to ⅞ inches) indiameter downwards at an angle of about 45° to about 60° through thecenter of the pole or pile. The length of the hole is approximately 2.5times the radius of the pole or pile, with a minimum hole length ofbetween 150 mm and 305 mm. Therefore, smaller structures with smallerradii may necessitate the use of a steeper drilling angle. Interrestrial piles, a first treatment hole is drilled or bored at orslightly below the ground line. One or more subsequent holes can then bedrilled or bored higher on the pole or pile, moving up and around thepole or pile in a spiraling pattern. Depending on the size of the poleor pile, holes should be spaced at either approximately 90° or 120°around the pole or pile, with a vertical distance of between about 150mm to about 325 mm (approximately 6 to 12 inches) between treatmentholes near the groundline, with a vertical distance of about 275 mm toabout 325 mm (approximately 12 inches) between treatment holes higher onthe pole or pile. For aquatic poles or piles, at a minimum, the lowestpart of a treatment hole should be above the waterline.

In other aspects of the invention, boring or drilling one or moretreatment holes into large timbers or glued-laminate beams comprisingboring or drilling holes into a narrow face of the member (usuallyeither the top or bottom). Treatment holes can be bored or drilledstraight down or up or slanted into these types of wooden structures.Slanting a treatment hole may be preferable, as it provides a largersurface area inside the holes for the escape of the MITC fumigant. As arule, the holes should be extended to within about two inches (51 mm) ofthe top or bottom of the member, and should be no more than four feet(1.22 m) apart.

Fumigants should not be applied into voids or when application holesintersect voids or checks. This precaution limits the risk that thefumigant product will accidentally be released into the environment.Care should be taken in the removal of wooden structures that have beentreated with the solid body, to ensure that the chemicals have moved outof the treatment hole and into the surrounding wood.

In certain aspects disclosed herein, once the solid body of dazomet hasbeen inserted into a treatment hole, accelerant may be added to thattreatment hole. As discussed above, possible accelerants may includecopper or zinc compounds in liquid form, including dispersed particles,although it would be readily apparent to one skilled in the art thatother copper- and zinc-containing compounds and other accelerants couldbe used as well. In certain embodiments of the invention, between about10 grams and about 30 grams of accelerant are added to the treatmenthole after the dazomet body has been inserted.

In certain aspects disclosed herein, the treatment hole is plugged afterthe solid body of dazomet (and, in certain aspects, accelerant) has beenadded to the treatment hole. The treatment hole may be pluggedimmediately after application of the product, and can be plugged with atight-fitting treated wood dowel or a removable plastic plug, althoughit would be readily apparent to one skilled in the art that othermethods of plugging the treatment hole could be used. There should besufficient room in treatment hole for the plug to be driven in withoutsquirting liquid chemical out of the hole or impacting the solid dazometbody.

By using a removable plug for plugging a treatment hole, additionaldazomet treatments can be applied to the same treatment holes over thecourse of subsequent months and years. By utilizing a solid body ofdazomet, as disclosed herein, a precise dose of fumigant can be easilyreapplied to the one or more treatment holes in a wooden structure oversubsequent treatment cycles by merely removing the plug and inserting afresh solid body.

A product for the internal remedial treatment of wood is manufactured,as disclosed herein, by uniformly blending a mixture of dazomet, alubricant, and a binder, and then compressing the blended mixture into asolid body. In certain embodiments, dazomet is powdered or granular,although it would be readily apparent to one skilled in the art thatother forms of solid dazomet could be used.

In certain aspects disclosed herein, the disclosed compositions furthercomprise a lubricant. The lubricant is selected from the groupconsisting of magnesium stearate, aluminum stearate, calcium stearate,talc, sodium benzoate, glyceryl mono fatty acid, glyceryl monostearate,glyceryl dibehenate, glyceryl palmito-stearic ester, hydrogenated oils,hydrogenated cotton seed oil, hydrogenated castor seed oil, andvinylpyrrolidone-vinyl acetate copolymer. However, it would be readilyapparent to one skilled in the art that other lubricants could be used.

In other embodiments, the disclosed compositions comprise a bindercomprising a polysaccharide. In one embodiment, the polysaccharide isselected from the group consisting of maltodextrin, dextrin, pectin,starch, modified starch, and starch derivatives. However, it would bereadily apparent to one skilled in the art that other binding agentscould be used.

In one aspect of the invention, the binder is a carbohydrate, including,monosacharides, oligosaccharides and polysaccharide, including starches,dextrins, maltodextrins, soy flour, dextrose, a polyol or a combinationthereof.

Suitable starches include granular starch and any starch thatgelatinizes to produce a viscous colloidal solution with high bindingpower, upon heating in an aqueous environment. The viscosity, binding,flow, tackifying film-forming properties of a starch may be adjusted byselecting, modifying, and/or gelatinizing a starch according to methodsknown in the art.

Suitable dextrins include polysaccharides formed during pyrolysis of dryor acid-modified starches. Dextrins may be used at higher solids levelsthan native or modified starches, creating stronger bonds, more tack andfaster-drying properties than pastes made from unmodified starch.

Soy flour, a co-product that remains after oil is extracted fromsoybeans. Soy flour requires less drying time, uses less water andproduces less waste than conventional glues.

Maltodextrins are glucose polymeric chains with a molecular weightbetween that of starch and a glucose syrup. Maltodextrins are highlywater soluble and are available both in powder and liquid form.

Dextrose is the fundamental monomer of all starch-based products and maybe used in liquid, granular, powder or crystalline form.

Polyols include but are not limited to sorbitol, maltitol, mannitol,xylitol, erythritol isomalt and isosorbide.

In one aspect of the invention, the binder is a monosaccharide, such asglucose or another monosaccharide, such as a monosaccharide or glucosesyrup.

In certain aspects disclosed herein, the mixture contains from about 80parts to about 99 parts dazomet, from about 0.25 parts to 5 partslubricant, and from about 0.5 parts to 15 parts binder. In a preferredembodiment, the mixture contains at least 97 parts dazomet. However, itwould be readily apparent to one skilled in the art that the proportionsof the ingredients of the mixture could differ, and that additionalingredients, including but not limited to a filler, could be added.

In certain aspects disclosed herein, the mixture is formed by blendinguntil the composition is uniform. Blending may be accomplished by usinga blender selected from the group consisting of V-blenders, double coneblenders, vertical blenders, and ribbon blenders. It would be readilyapparent to one skilled in the art, however, that other devices could beutilized.

In embodiments of the present invention, the mixture is blended for atleast 3 minutes, at least 5 minutes, at least 10 minutes, and at least20 minutes.

In certain aspects disclosed herein, the mixture is compressed into asolid body essentially free of water. As used herein, “essentially freeof water” means a solid body of powdered or granular dazomet to which nowater has been added during manufacture. A solid body, essentially freeof water, ensures that the dazomet remains stable and does notsignificantly decompose, until application.

In certain aspects, as disclosed herein, the mixture is compressed usingeither a single-punch tablet press or a rotary tablet press, although itwould be readily apparent to one skilled in the art that other devicescould be used.

EXAMPLES

The following Examples are only illustrative and are not intended tolimit the scope of the invention in any manner. It will be readily seenby one of ordinary skill in the art that the present invention fulfillsall of the objectives set forth above. It is therefore intended that theprotection granted herein be limited only by the definition contained inthe appended claims and equivalents thereof.

Example 1 Preparation of a Dazomet Composition

A wood preservative composition comprising dazomet (98%Tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione) was prepared from97.00 parts of granular dazomet, 1.00 parts Lubritab, a hydrogenatedvegetable oil, and 2.00 parts Maltrin M-200 a maltodextrin. Thecomponents were mixed until evenly dispersed. The resulting blend wasfree flowing and did not clump or cake.

Example 2 Preparation of a Dazomet Composition

A wood preservative composition comprising dazomet (98%Tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione) was prepared from97.50 parts of granular dazomet, 0.50 parts Lubritab, a hydrogenatedvegetable oil, and 2.00 parts Maltrin M-200 a maltodextrin. Thecomponents were mixed until evenly dispersed. The resulting blend wasfree flowing and did not clump or cake.

Example 3 Preparation of a Dazomet Composition

A wood preservative composition comprising dazomet (98%Tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione) was prepared from95.00 parts of granular dazomet, 1.00 parts Lubritab, a hydrogenatedvegetable oil, and 4.00 parts Maltrin M-200 a maltodextrin. Thecomponents were mixed until evenly dispersed. The resulting blend wasfree flowing and did not clump or cake.

Example 4 Compression of a Dazomet Composition

The blended composition prepared in Example 1 was used to form a solidbody of dazomet. The mixture was compressed under pressure using aStokes Model T-4, 12-ton dual motion ceramic compacting press. To formthe tablet or rod, the blended formulation was metered into a cavityformed by two punches and a die, and then the punches were compressed tofuse the material. After compression, the lower punch was raised toeject the tablet or rod. The resulting tablets or rods had good hardnessand friability and were resistant to picking and sticking to the punchfaces. The resulting tablets were uniform in weight or density andshowed no signs of defects such as laminating or chipping. The finishedtablets or rods, measured approximately 3 inches in length with adiameter of about one half-inch.

Example 5 Compression of a Dazomet Composition

The blended composition prepared in Example 2 was used to form a solidbody of dazomet. The mixture was compressed under pressure using aStokes Model T-4, 12-ton dual motion ceramic compacting press. To formthe tablet or rods, the blended formulation was metered into a cavityformed by two punches and a die, and then the punches were pressedtogether with great force to fuse the material together. Aftercompression, the lower punch was raised to eject the tablet or rod. Theresulting tablets or rods had good hardness and friability and wereresistant to picking and sticking to the punch faces. The resultingtablets were uniform in weight or density and showed no signs of defectssuch as laminating or chipping. The finished tablets or rods, measuredapproximately 1.5 inches in length with a diameter of about 5/16 of aninch.

Example 6 Compression of a Dazomet Composition

The blended composition prepared in Example 3 was used to form a solidbody of dazomet. The mixture was compressed under pressure using aStokes Model T-4, 12-ton dual motion ceramic compacting press. To formthe tablet or rod, the blended formulation was metered into a cavityformed by two punches and a die, and then the punches were pressedtogether with great force to fuse the material together. Aftercompression, the lower punch was raised to eject the tablet or rod. Theresulting tablets or rods had good hardness and friability and wereresistant to picking and sticking to the punch faces. The resultingtablets were uniform in weight or density and showed no signs of defectssuch as laminating or chipping. The finished tablets, or rods, measuredapproximately 1.5 inches in length with a diameter of about one 5/16 ofan inch.

What is claimed is:
 1. A composition comprising a flowable mixture ofbetween 93% and 96% solidtetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione, by weight of thecomposition; between 0.5% and 5.0% of a saturated oil, by weight of thecomposition; and between 1% and 5% of a polysaccharide, by weight of thecomposition.
 2. The composition of claim 1, wherein the solidtetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione is in the form ofgranules or a powder.
 3. The composition of claim 1, wherein thesaturated oil is a hydrogenated oil.
 4. The composition of claim 3,wherein the saturated oil is a hydrogenated vegetable oil.
 5. Thecomposition of claim 1, wherein the polysaccharide is a starch.
 6. Thecomposition of claim 5, wherein the starch is a maltodexrin.
 7. Thecomposition of claim 1, wherein the composition is water-free.
 8. Aproduct for internal remedial treatment of wood consisting of asheathless rod of a compressed dazomet composition, wherein the dazometcomposition consists of between 90% and 96% solidtetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione, by weight of thecomposition; between 0.5% and 5.0% of a saturated oil, by weight of thecomposition; between 1% and 5% of a polysaccharide, by weight of thecomposition; and an accelerant; wherein the rod has a length of about100 millimeters to about 350 millimeters; and wherein the dazometcomposition is flowable before compression.
 9. The product of claim 8,wherein the rod has a diameter of about 5 millimeters to about 30millimeters.
 10. The product of claim 8, wherein the rod has a weight ofbetween 10 grams and 500 grams.
 11. The product of claim 8, wherein theaccelerant is selected from the group consisting of copper naphthenate,copper sulfate, copper carbonate, basic copper carbonate, copperhydroxide, cupric oxide, cuprous oxide, copper oxychloride, copperdimethyldithiocarbamate, copper borate and zinc naphthenate.
 12. Theproduct of claim 8, wherein the solidtetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione is in the form ofgranules or a powder.
 13. The product of claim 8, wherein the saturatedoil is a hydrogenated oil.
 14. The product of claim 13, wherein thesaturated oil is a hydrogenated vegetable oil.
 15. The product of claim8, wherein the polysaccharide is a starch.
 16. The product of claim 15,wherein the starch is a maltodexrin.
 17. The product of claim 8, whereinthe dazomet composition comprises between 93% and 96% solidtetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione, by weight of thecomposition.
 18. A flowable mixture consisting of between 90% and 96%solid dazomet, by weight of the composition; between 0.5% and 5% of asaturated oil, by weight of the composition; and between 1% and 5% of apolysaccharide, by weight of the composition.
 19. The composition ofclaim 18, wherein the solid dazomet comprisestetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione in the form ofgranules or a powder.
 20. The composition of claim 19, wherein thehydrogenated oil comprises a hydrogenated vegetable oil.
 21. Thecomposition of claim 18, wherein the saturated oil is a hydrogenatedoil.
 22. The composition of claim 18, wherein the polysaccharide is astarch.
 23. The composition of claim 22, wherein the starch comprisesmaltodexrin.
 24. A product for internal remedial treatment of woodcomprising the composition of claim 18 compressed into a solid body. 25.The product of claim 24, wherein the solid body is a rod.
 26. Theproduct of claim 25, wherein the rod has a diameter of about 5millimeters to about 30 millimeters, and a length of about 100millimeters to about 350 millimeters.
 27. The product of claim 25,wherein the rod has a weight of between 10 grams and 500 grams.
 28. Theproduct of claim 24, wherein the product is sheathless.